With the rapid development of wireless communication systems and the widespread use of various mobile terminal products, there is an increasing demand for higher transmission rates in wireless communication systems. As a result, the transmission power is significantly increased. Therefore, to avoid an excessive amount of transmission power, a relay transmission system (RTS) has been adopted in the deployment and design of wireless communication systems; i.e., a relay station (RS) is added between a source station and a destination station to assist in transmission. Accordingly, more attention is being paid to control the power of the RTS.
The power design of a conventional RTS can only control the transmission power of the source station, the RS and the destination station separately, i.e., set the transmission power of the source station, the RS and the destination station separately according to their respective power limitations. As a result, an optimum power distribution cannot be achieved between the source station, the RS and the destination station under the limitation of a total transmission power, nor can an optimum transmission efficacy be achieved through the design of transmitters for the source station, the RS and the destination station.
Accordingly, it is necessary to provide a method for the power distribution of a source station, an RS and a destination station so that the optimum transmission efficacy and the optimum power distribution can be achieved in an RTS under the limitation of a transmission power.